Overall goals of this project are to: define the nature of the genes which code for, or otherwise affect the structure of immunoglobulins (Igs), to understand the regulatory processes which control Ig gene expression; to understand the mechanisms which lead to the synthesis of highly specific antibody molecules, and the nature of genes which influence and control immune responses. We prepare immunological reagents which detect structural differences between genetically controlled polymorphic forms of rabbit Igs (Ig allotypes) and between classes and subclasses, types and subtypes of their polypeptide chains. We have been using both immunological and chemical approaches to define the structural differences as well as to learn more about the chromosomal organization of genetic information for structure and expression of antibody molecules. We utilize the information and the reagents in studies including breeding experiments, investigation of the ontogeny and differentiation of cells which produce Igs intracellularly, as secreted products, and as membrane-associated receptors, and investigation of factors which influence and regulate phenotypic expression of alleles and chain types.